Hurricane Irene Weakens on its Approach to North Carolina

By: Dr. Jeff Masters , 7:58 AM GMT on August 27, 2011

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As of 300AM EDT, Hurricane Irene was located at 33.7N, 76.5W, 60 miles south of Cape Lookout. It was moving north-northeast at 14 mph with maximum sustained winds of 90 mph, making it a Category 1 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 952 mb.

Hurricane warnings are in effect for the US Atlantic coast from the Little River inlet in North Carolina to Sagamore Beach, Massachusetts. Tornado watches are also in effect for the North Carolina/Virginia/Maryland coast. Figure 1 shows the hurricane, tropical storm, and tornado watches and warnings for Irene. Remember, a hurricane warning means hurricane conditions are expected, and tropical storm force winds (greater than 34 mph) will occur within 36 hours. Tropical storm warning means that tropical storm force winds are expected in the next 36 hours, but hurricane conditions are not. A tropical storm watch means tropical storm force winds are possible within 48 hours.

To find out if you need to evacuate, please contact your local emergency management office. They will have the latest information. People living in New York City can find their evacuation zone here or use this map. FEMA has information on preparing for hurricanes. FEMA also has a blog describing their response to Irene.


Figure 1 Map of watches and warnings taken at 225AM EDT, August 27, 2011

Satellite Views
Figure 2 shows that Irene is a large storm, with outflow reaching from South Carolina to Long Island, NY. Irene's eye is not visible.


Figure 2 IR satellite view of Irene taken at 226AM EDT, August 27, 2011

Track Forecast

Irene is forecast to make landfall on the North Carolina coast Saturday morning as a category 1 storm with sustained winds around 90 mph. I believe that Irene's center of circulation will make landfall somewhere between Cape Lookout and Okracoke on the Outer Banks around 9-10 am. Irene should then move roughly north, along the mid-Atlantic coastline before making landfall in western Long Island. However, it is important to not focus solely on the track forecast. Irene is a large storm with a large windfield and equally large areas of storms and showers. It's impact will be felt over a wide swath of the northeastern US.


Figure 3 Official track forecast of Irene at 11PM EDT, Aug. 26.

Irene and Flooding
Six to ten inches of rain are possible along Irene's track from North Carolina north into New England, with 15 inches possible in isolated areas. Radar estimates indicate at least 5 inches have already fallen near Morehead City, NC. As a result, flooding is very likely. The Hydrometeorological Prediction Center (HPC) has issued their Significant River Flood Outlook for the next five days shown in figure 4. HPC thinks that river flooding from the Delmarva peninsula to northwestern Maine is likely, while river flooding in much of the rest of the northeastern US is possible.


Figure 4 Significant River Flood Outlook issued by HPC.

Impacts

Tropical storm forces winds are occuring at Cape Lookout now, with hurricane force winds expected on the North Carolina coast later today. Use this Wundermap to keep track of how the winds are behaving around the North Carolina coastline. Within the hurricane warning area in North Carolina, storm surge is expected to be 6-11 feet above ground. This is our storm surge forecast map. To see how high the tides are running, NOAA has an excellent page collecting all of the relevant tide gauges.

People living on the the east coast of the US from the Carolinas to Cape Cod should continue monitoring Irene and be in the process of finishing their hurricane preparations. If you have not started preparing for this storm, start immediately. If an evacuation order is given, please follow it, unless it is unsafe to do so. Irene will be a large storm, impacting areas far from the storm center track.

Links

If you're curious about power outages, here are some maps: Dominion Power Outage Map (NC/VA), Progress Energy Outage Map (NC/SC), and NOVEC Outage Map (Northern Virginia).

Dr. Masters will have a new blog entry this morning, and there will be another blog this afternoon. I'll be back with another blog entry late tonight.

Stay safe,

Dr. Rob Carver

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a stop sign fell down and a few limbs,OZ is funny...lol
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Quoting P451:
Why it does not matter that the storm is presently 100mph but will "only" be 75mph when it hits western Long Island, NY.



We're talking wind field. Irene has a huge wind field and it is one that will actually grow in size as it heads north. Not depicted in the image I wanted to keep it simple to show how losing the 100mph ring is absolutely meaningless. She will not lose the wind field as a result of losing that 100mph ring in fact the wind field will spread out!

While the storm may lose 100 mph rating and drop to 75 the bottom line is that 100 mph wind is in the tiniest region. Winds 75 and above are spread out quite far. They will spread out even further as the storm heads north.

While some are downplaying the 75mph they either don't know or are forgetting about the structure of the storm and where these winds are. 100 dropping to 75 is absolutely meaningless at this point for the upper mid-atlantic and north east.

This is going to be quite a damaging storm.

Actually, it makes all the difference. "An often-misunderstood aspect of hurricane winds is the potential for increased damage as wind speeds increase. The forces against structures do not increase linearly, they increase exponentially (power of 3), and as wind speed increases." Source
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Quoting drg0dOwnCountry:
less and less dry air intrusion...
look at her!!!!!! firing that deep convective blob on her west side!! wow,call her alot of things,but quitter is not one of them!!
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Morning, dewey. I'm watching. It looks nasty out there. And where's the D2?
Member Since: August 18, 2008 Posts: 0 Comments: 884
Looks like we'll end up getting the extratropical remnants. At the moment, roughly around 990mb after it leaves North America.

Considering how low its pressure is, I wonder how much of that will translate once its lost its tropical characteristics.
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he was waiting for that red awning to fly off during the night,it was wobbling quite a bit. highest gust i seen reported so far is 93mph by weather spotter,anyone heard of higher? when she crosses NC,gets to VA some of those 100-125mph winds might get to the surface,i think they were at like 2-4 thousand feet.
Member Since: September 18, 2010 Posts: 0 Comments: 5234
the debre i thought i seen on cam was birds lol very funny
these guys have upstream going and hand held instrament that has recorded 959.8 pressure reading
these guys are running off site crazymother.tv
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Quoting Jtownboy:

He is cracking me up now thats a man that loves weather


yup,fo sure
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Quoting yonzabam:


It's a little bit complicated for me, too, as a pop-up blocker interferes with it.

I have to click on 'link' or 'image', if it's a pic, then a pop-up noise follows with a yellow line to click. I click the line, then click on 'link' or 'image' again. A box appears top left. Delete letters in box, then paste URL. Then click 'OK'. Done.


Ah. Thank you! Could be my Kaspersky interfering.
Member Since: August 18, 2008 Posts: 0 Comments: 884
Quoting entrelac:
IIRC he was banned for incessantly linking to his non-WU blog/site. That is against house rules.

I seem to remember there being a little something more to it but that is the main gist.
thanks
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Quoting Jtownboy:

He is cracking me up now thats a man that loves weather


He is definitely a trip. This is a weird storm. Such low pressures but yet no real wind in the area of that reading.
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Quoting Vero1:
"Hurricane Police"?...is that the new agency created by Homeland Security?


Who knows... ;)

But I think as much as you marvel at the strength and sometimes the aesthetics of them, dry air and shear prove their complexity and mystery more than any other factor. Something so fierce and deadly can be unwound or at least tempered by a bit of stable air and crosswinds. Even then, some systems collapse at the mere mention of it, whereas others keep fighting through regardless of the obstacles. Sure, cold water can do a similar effect, but it needs hot water nearly as much as living organisms need oxygen, so it's not quite the same.

Maybe that's just me.

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Looks like rain coming in now with a breeze.
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less and less dry air intrusion...
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Quoting weatherwart:
I've never had luck trying to post links on this site.


It's a little bit complicated for me, too, as a pop-up blocker interferes with it.

I have to click on 'link' or 'image', if it's a pic, then a pop-up noise follows with a yellow line to click. I click the line, then click on 'link' or 'image' again. A box appears top left. Delete letters in box, then paste URL. Then click 'OK'. Done.
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Quoting CybrTeddy:
Latest radar image indicates Irene has made landfall in Morehead City as a Category 1 hurricane, the first hurricane to hit the USA since Hurricane Ike in September 2008.
yes we broke the 3 year streak. we still havent broke the 6 year streak of a major hitting the US though although i hope that doesnt happen. Irene maybe a cat 1 at landfall but still a very powerfull storm..
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Quoting CybrTeddy:
Latest radar image indicates Irene has made landfall in Morehead City as a Category 1 hurricane, the first hurricane to hit the USA since Hurricane Ike in September 2008.
thats a bad location,seems to me IMHO
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Irene is going to make landfall as a 90mph hurricane... she has cat 3 storm surge and she is very powerfull
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Quoting emcf30:
Well at least he got his 959MB. LOL

He is cracking me up now thats a man that loves weather
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i did see some small debre watching this video .
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and it hit 959.8 without distructive winds at the point of pressure reading .im watching via ustream
http://www.ustream.tv/
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hes got 10 more mb possibly if hes where i think he is lolololololol, this hurricane is special he says....lololol
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Quoting HurricaneHunterJoe:
i dont know what he did to get banned,hope he has his own blog,i could have fun there
IIRC he was banned for incessantly linking to his non-WU blog/site. That is against house rules.

I seem to remember there being a little something more to it but that is the main gist.
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Latest radar image indicates Irene has made landfall in Morehead City as a Category 1 hurricane, the first hurricane to hit the USA since Hurricane Ike in September 2008.
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Well at least he got his 959MB. LOL
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959.9 WOW WOW WOW
Member Since: September 18, 2010 Posts: 0 Comments: 5234
pressure is on ground hand held instrament is 959.9
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156. Vero1
A good interactive site to follow Tropical Storms:

http://www.stormpulse.com/
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Quoting oakland:


I think he left and went to Raleigh where his daughter(?) lives.
glad he's safe!!
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Maybe,nhc will call it Cape Lookout for landfall
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Hope you guys up there are not doing bad.

Based on some WX station reports I've been looking at from NC... it doesn't appears to be too bad so far winds gusting in the 30MPH to 45MPH range.

Surely appears the worst of the WX is being kept by Irene to her NE and E quadrants which is good.
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i dont know what he did to get banned,hope he has his own blog,i could have fun there
Member Since: September 18, 2010 Posts: 0 Comments: 5234
OZ just east of Beaufort??anybody got a better locale than that? this guy is hilarious!!!
Member Since: September 18, 2010 Posts: 0 Comments: 5234
150. Vero1
Quoting Cotillion:
G'luck to those in NC. Good that she's continued her slow weakening, much better than the alternative offered by the models a few days ago. Been an interesting storm, one of those systems that just had enough roadblocks in front to stop her.

Messrs Dry-Air and Shear: The Hurricane Police.
"Hurricane Police"?...is that the new agency created by Homeland Security?
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Quoting P451:
Well, now these couple of days have come to an important point in time for hurricanes riding up the east coast.

Most importantly for folks in DE, NJ, NYC, CT.

This is where they would show whether or not they were going to slip inland and decay, ride the coast, or slide east out to sea.

Irene has continued steadily northward and is showing that it wants to ride the coast right up to western Long Island.

The next five hours or so will tell the tale but at this point it appears the storm is for real, it is coming, and it is very strong.

While you can see continental air being drawn in to shut off the southern half of her cdo this is in no way the end of the storm.

This is not like the tropics where this process would rapidly kill a storm.

That is not going to happen. That is not how hurricanes behave heading up the coast. Baroclinic processes will keep her a very strong storm. Her winds will not come down much from here until landfall in Long Island. She is still at 100 and that means she would be anywhere from 75 and up when she hits up north.




Westchester County, NY (Due north of Manhattan/Bronx):

NORTHEAST WINDS 50 TO 70 MPH...BECOMING NORTHWEST IN THE
AFTERNOON. GUSTS UP TO 90 MPH.

New York City (Manhattan):

NORTHEAST WINDS 55 TO 70 MPH...BECOMING NORTHWEST 55 TO
65 MPH IN THE AFTERNOON. GUSTS UP TO 80 MPH.

New Jersey Coastline (Monmouth County):

NORTH
WINDS 55 TO 75 MPH WITH GUSTS UP TO 85 MPH.





do you think she can wrap moisture back around her coc and become more symmetrical once she gets out of OBX and back over water?
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looks like the last center will be right off tip of harker island,whoever it was that called that kudos to you!!~
Member Since: September 18, 2010 Posts: 0 Comments: 5234
G'luck to those in NC. Good that she's continued her slow weakening, much better than the alternative offered by the models a few days ago. Been an interesting storm, one of those systems that just had enough roadblocks in front to stop her. Still a big and threatening system, though.

Messrs Dry-Air and Shear: The Hurricane Police.
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Quoting drg0dOwnCountry:


looks a bit better



agreed. in the past 4 frames she is definitely starting to rebuild the western quads....considering how much dry air she just chewed on im shocked to see the eyewall this intact. she has that dry air pouch in her western quads, but considering how close she is hanging to the water she may have time to recover. i would assume if she made a landfall into direct land with no out back to water the dry air + land shear would have caused even more destabilization, but the fact that she is gonna be back over water tells me that this may build a strong coc back relatively quickly, especially once she is out of OBX.
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LOL im robust enough to last................lololololololololol......hes great
Member Since: September 18, 2010 Posts: 0 Comments: 5234
LOL I love this guy OZ, I heard that he blogged on here and got banned out, but this guy could do standup during a hurricane.........love it
Member Since: September 18, 2010 Posts: 0 Comments: 5234
Quoting WxLogic:
Good Morning...


morning WX
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.